A reservoir is an area where water is collected and stored for future use. These water bodies are integral to managing water resources, providing a readily available supply. They function as large storage containers, ensuring water availability across varying environmental conditions and demands.
How Reservoirs Form and Their Main Types
Reservoirs can form through natural processes or human intervention. Natural reservoirs often form in geological depressions, such such as those created by ancient glacial activity, or within extinct volcano craters. They can also form behind natural obstructions that impede water flow.
Most large reservoirs are artificial, created by constructing a dam across a river or stream. This barrier causes water to back up, filling the valley or an excavated area to form a large body of water. These artificial impoundments are categorized as on-stream, built directly on a riverbed, or off-stream, receiving water diverted from a nearby source.
Reservoirs are also classified by location: surface reservoirs are visible bodies of water, while underground reservoirs store water within aquifers. Artificial reservoirs are specifically engineered to meet various water management needs, unlike natural lakes which can also store water.
Diverse Purposes of Reservoirs
Reservoirs fulfill multiple functions, supporting human populations and economic activities. A primary purpose is to provide a reliable source of drinking water for communities, collecting precipitation and river flow for treatment and distribution. This stored water ensures a continuous supply, particularly during drier periods.
Another significant use is agricultural irrigation. Reservoirs store vast quantities of water that can be released to water crops, supporting agricultural productivity. This mitigates the impact of water scarcity in drought-prone regions, allowing farmers to manage water distribution effectively.
Reservoirs are also instrumental in flood control. By impounding excess water during heavy rainfall or snowmelt, they prevent downstream flooding and protect communities and infrastructure. The controlled release of stored water helps regulate river flow, reducing the risk of catastrophic overflow.
Many reservoirs are designed for hydroelectric power generation. Water stored at a higher elevation behind a dam is released through large pipes, turning turbines that generate electricity as it flows downward. This process converts the potential energy of the stored water into renewable electrical energy.
Reservoirs offer opportunities for recreational activities like fishing, boating, and other water sports. They contribute to local economies and provide leisure spaces for the public. Some reservoirs also contribute to environmental conservation by stabilizing river flows and providing habitats for aquatic life.
Essential Parts of a Reservoir System
Artificial reservoir systems comprise several interconnected components. The most prominent part is the dam, a large barrier constructed across a river or valley that holds back water to form the reservoir. Dams are engineered structures that retain water, creating the necessary storage volume.
Spillways are designed to safely release excess water from the reservoir when its capacity is reached, typically during high inflow. These structures prevent water from overtopping the dam, which could compromise its structural integrity. Spillways can be controlled with gates or be uncontrolled, allowing water to flow freely once it reaches a certain level.
Intake structures draw water from the reservoir for distribution or use. These structures often consist of towers or pipes with openings at various depths, allowing operators to select the most suitable water level. The collected water is then conveyed to treatment plants, power generation facilities, or irrigation systems.